Bergenhus Fortress and Rosenkrantz Tower, Bergen (must see)

The Bergenhus Fortress has been a royal seat and residence, an ecclesiastical center, and a military power base. The grounds of Bergenhus comprise Holmen, Koengen, and Sverresborg. The history of the fortress reaches back to the Middle Ages, when Holmen developed into a royal and ecclesiastical center. In the 16th and 17th centuries, the complex was increasingly fortified, and during the 1600s Holmen, Koengen, and Sverresborg were joined into one large military site.

The fortress was under attack only once, during the Second Anglo-Dutch War. In the Second World War, Bergenhus was once again in military use. This time, however, it was the German occupying forces that used the fortress as one of their headquarters. Bergenhus has been under continuous commandantship since 1628. Presently, around 220 military and civilian personnel have their everyday place of work at the fortress.

The Rosenkrantz Tower is the dominant building of the fortress complex. It was named for governor Erik Rosenkrantz. The tower got its present form during Rosenkrantz's period as governor, 1560–1568. There is a much older part of the tower: a medieval structure known as the “Keep by the Sea.” It was built by King Magnus the Lawmender around 1270.

The other major medieval structure to survive is Håkon's Hall, built between 1247 and 1261 by King Håkon Håkonsson. Several churches also once stood on Holmen, including Bergen's medieval cathedral, Christ Church. The churches and other ecclesiastical buildings were demolished around 1530–1531, largely for military reasons, as Bergenhus was being strengthened. The fortress became a purely military establishment after the separation of civil and military authority in 1660.